Technical Field
The invention relates to a power conversion technique, and particularly relates to a flyback-based power conversion apparatus.
Related Art
A main application of power conversion apparatus is to convert an input voltage with a high voltage value and low stability that is provided by a power company into a direct current (DC) output voltage with a low voltage value and good stability that is suitable for various electronic devices. Therefore, the power conversion apparatus is widely applied in various electronic devices such as computers, office automation equipment, industrial control equipment and communication equipment, etc.
A control structure in today's power conversion apparatus generally adopts a pulse width modulation (PWM) control chip. Moreover, in order to avoid damage of the power conversion apparatus due to phenomenon of over temperature (OT), over voltage (OV), and over current (OC), etc., today's PWM control chip is generally configured with a plurality of independent detection pins to respectively execute/perform detection of over temperature protection (OTP) and detection of over voltage protection (OVP). In other words, a single detection pin of today's PWM control chip only corresponds to one kind of related detection function at most, so that a whole cost of the PWM control chip is eventually increased.